Elongaticonidia W.J. Li & E. Camporesi & K.D. Hyde, gen. nov.
Etymology: Referring to the conidial shape is elongated.
Lecanoromycetes, Ostropomycetidae, Ostropales, genera incertae sedis
Saprobic on dead spines of Rosa canina. Sexual morph: undetermined. Asexual morph: Conidiomata black, pycnidial, solitary to gregarious, subepidermal, immersed, globose to subglobose, ostiolate. Ostiole short, centrally located. Conidiomatal wall composed of thick-walled, dark brown to brown cells of textura angularis. Conidiophores reduced to conidiogenous cells. Conidiogenous cells forming from inner layers of conidiomata, pale brown to hyaline, forming from inner wall layers of conidiomata, pale brown to hyaline, holothallic, ampulliform to cylindrical, discrete, determinate, smooth-walled, consisting of basal thicker-walled cells which become flared at the inception of conidiogenesis. Conidia hyaline, arthric, formed by disarticulation of the conidial chain, produced in simple unbranched chains with the youngest conidium at the base, elongated, 1-septate, deeply constricted at septum, bearing unbranced, cellular, flexuous, appendages.
Figure 1 – (redrawn from Li et al. 2020) a Vertical section of conidiomata. b Conidiogenous cells and developing conidia. c,d Conidia. Scale bars: a = 100 µm, b = 10 µm, c,d = 5 µm.
Notes: Phylogenetic study based on LSU sequence data shows Elongaticonidia close to Mulderomyces, but it formed a seprate banche in Ostropales (Lecanoromycetes). Morpholgically, Elongaticonidia is distinct from Mulderomyces in form of conidia and conidiogenous cells. Elongaticonidia has holothallic conidiogenous cells and elongated 1-septate, deeply constricted at septum conidia bearing 4–8, unbranded, flexuous appendages. Mulderomyces has proliferating sympodial, subcylindrical conidiogenous cells and cylindrical, 2–6-septate, prominently constricted at septa, with mature conidia breaking into phragmospores (Crous et al. 2016b).
Li WJ, McKenZie EHC, Liu JK, Bhat DJ, Dai DQ, Caporesi E, Tian Q, Maharachcikumbura SSN, Luo ZL, Shang QJ, Zhang JF, Tangthirasunun N, Karunarathna SC, Xu JC, Hyde KD (2020) Taxonomy and phylogeny of hyaline-spored coelomycetes. Fungal Diversity 100: pages279–801.